It is well known that ordinary catgut is currently losing attention as a surgical suture filament because of its biodegradation properties which are not favorable. Indeed, it has been shown that, when catgut is in contact with the living tissues surrounding a wound which has been stitched, it degrades enzymatically and loses its mechanically properties quite rapidly. This drawback can be somewhat lessened by subjecting the collagen of the catgut to tanning with chromium salts, however, such procedure has disadvantages since chromium compounds are toxic. Further, catgut sutures, chromated or not, induce unwanted tissue reactions, especially for the first days, such reacting being much less significant with more modern suture materials.
Thus, there is now a tendency to more and more replace the catgut sutures by synthetic filaments or braids made of polyesters the degradation of which has a profile different from that of catgut since it is not enzyme catalyzed. In short, when such polyesters (polyoxyacetyl esters such as polyglycolic or polyactic esters) are used as suture material, they will retain their tensile properties longer than catgut (even chromium treated) although the overall resorption time is about the same. Details on these questions will be found in the following references: ENCYCLOPEDIA OF POLYMER SCIENCE & TECHNOLOGY, Vol. 1 (Supplement), p. 587-596. P. Y. WANG et al: Structural Requirements for the Degradation of Condensation Polymer in Vivo, Polymer Science & Technology, Plenum Press (1973). K. SUGIMACHI et al: Evaluation of Absorbable Suture Materials in Biliary Tract Surgery, CA 89, 30728y. E. L. Howes: Strength Studies of Polyglycolic Acid versus Catgut Sutures of the Same Size, CA 79. 57648c. A. B. KOVACS et al: Comparative Study of Tissue Reactions to Various Suture Materials (Catgut, Silk and Polyesters), CA 72, 11183z.